Blackhawk Network (HAWK) soared above a buy point in huge volume Thursday, the lone bright spot in a short new-highs list. The operator of a global network of prepaid gift cards gapped up and jumped 2.38, or nearly 9%, to 30.23 after announcing an acquisition. The stock, which went public in April 2013, cleared a 29.13 flat-base buy point in triple its average daily trade.